this can be set during ur install. so u need to uninstall it first then install it again. then what u need to do is select lot of stuff as a default install setting rather then basic or normal. then alongside the instalation progress many windows wil appears and u must watch out for a windows that show all format including the audio format and video format. u just need to select all n follow the rest procedure. this pc won let me intsall anything so i cannot give u exact tips.. but all u need to do is uninstall and instal;l back and watch each windows carefully. u will know waht to chose when the windows is there. if i remember correctly it was option to enable thumnail veiw in windows explorer n what u need to watch is, watch the windows that list all video n audio format n choose all rather then default. then there u goo. all format will have thumnail veiw in ur system except some that have been disable by the codecs or maker.

susendeep dutta

August 6, 2012 at 2:56 pm

Update the codec pack you are using to play the media files.There are two ways you can do it.

" Recent versions of the codec pack contain the Media Preview and Icaros thumbnail plugins. Those should give proper thumbnails for these file formats. So if you are using an old version of the pack, consider upgrading.

The tips below only apply when using the legacy thumbnail shell extension from Microsoft. It is not relevant when using Media Preview or Icaros!

By default Windows 7 uses its own decoders for video formats such as H.264. The Microsoft decoders do not always work properly when Explorer want to generate a thumbnail. The solution is to change the preferred decoder for H.264 video. You can use the Win7DSFilterTweaker tool (which is included in the codec pack) to change the preferred decoders in Windows 7 (and 8). For thumbnails to work properly you should choose either USE MERIT (recommended), ffdshow, or LAV.

After you have changed the settings, you need to reboot to make the settings take effect in Windows Explorer. You may also need to clear the thumbnail cache."